Dielectric properties of BaMg1∕3Nb2∕3O₃ doped Ba_0.45Sr_0.55Tio₃ thin films for tunable microwave applications

Abstract

Ba(Mg 1=3 Nb 2=3 ÞO 3 (BMN) doped and undoped Ba 0:45 Sr 0:55 TiO 3 (BST) thin films were deposited via radio frequency magnetron sputtering on Pt/TiO 2 /SiO 2 /Al 2 O 3 substrates. The surface morphology and chemical state analyses of the films have shown that the BMN doped BST film has a smoother surface with reduced oxygen vacancy, resulting in an improved insulating properties of the BST film. Dielectric tunability, loss, and leakage current (LC) of the undoped and BMN doped BST thin films were studied. The BMN dopant has remarkably reduced the dielectric loss ($38%) with no significant effect on the tunability of the BST film, leading to an increase in figure of merit (FOM). This is attributed to the opposing behavior of large Mg 2þ whose detrimental effect on tunability is partially compensated by small Nb 5þ as the two substitute Ti 4þ in the BST. The coupling between Mg Ti charged defects. The carrier transport properties of the films were analyzed in light of Schottky thermionic emission (SE) and Poole-Frenkel (PF) emission mechanisms. The result indicated that while the carrier transport mechanism in the undoped film is interface limited (SE), the conduction in the BMN doped film was dominated by bulk processes (PF). The change of the conduction mechanism from SE to PF as a result of BMN doping is attributed to the presence of uncoupled Nb Ti sitting as a positive trap center at the shallow donor level of the BST.

Electrochemical Detection of 2‐Nitrophenol Using a Glassy Carbon Electrode Modified with BaO Nanorods

“…The farther subdivisions of spin orbitals of Ba3d 5/2 and Ba3d 3/2 are found at 781.0 eV and 797.0 eV respectively. Both peaks of Ba3d 5/2 and Ba3d 3/2 level have confirmed the existence of Ba 2+ oxidation [45,46] . Besides this, O1s XPS spectra as in Figure 2(b) is shown two peaks at 529.0 eV and 533.0 eV respectively.…”

“…Both peaks of Ba3d 5/2 and Ba3d 3/2 level have confirmed the existence of Ba 2 + oxidation. [45,46] Besides this, O1s XPS spectra as in Figure 2(b) is shown two peaks at 529.0 eV and 533.0 eV respectively. The peak at 529.0 eV can be assigned for O 2 À in BaO and the peak located at 533.0 eV is for À O group on the surface of BaO NRs.…”

Densification and Proton Conductivity of La1-xBaxScO3-δ Electrolyte Membranes

“…The Ba3d spectra split into the Ba3d5/2 and Ba3d3/2 components (the spinorbital splitting is 15.3 eV) due to the spin-orbit interaction. The Ba3d5/2 binding energy is 780.0 eV, which corresponds to the Ba 2+ state [50,51]. The Ba3d and Co2p spectra overlap substantially.…”

Electronic Structure, Chemical Bonding, and Electrocatalytic Activity of Ba(Fe0.7Ta0.3)O3−δ Compounds

“…The deconvoluted high-resolution XPS spectra of Ba 3d 5/2 in BFTO compounds is shown in Figure . The Ba 3d exhibits two XPS components, which correspond to Ba 3d 5/2 and Ba 3d 3/2 associated with spin–orbit coupling, located at lower and higher binding energies, respectively. − The high-resolution XPS line of Ba 3d 5/2 (Figure ) reveals the presence of two clearly visible components, and the deconvolution of peaks using the Gaussian function are also shown in Figure . These clearly visible components are fitted mainly with two peaks positioned at 779.50 eV (red) and 778.38 eV (green).…”